refactor: enforce frontend view model boundaries

src/features/tbank-connection/ui/TbankConnectionSection/TbankConnectionSection.test.tsx

@@ -21,26 +21,31 @@ const brokerageAccountsQueryKey = apiQueryClient.queryOptions(
 	"get",
 	"/api/v1/brokerage-accounts",
 ).queryKey;
+
 const portfolioQueryKey = apiQueryClient.queryOptions(
 	"get",
 	"/api/v1/brokerage-accounts/{accountId}/portfolio",
 	{ params: { path: { accountId: "account-1" } } },
 ).queryKey;
+
 const operationsQueryKey = apiQueryClient.queryOptions(
 	"get",
 	"/api/v1/brokerage-accounts/{accountId}/operations",
 	{ params: { path: { accountId: "account-1" } } },
 ).queryKey;
+
 const stockQueryKey = apiQueryClient.queryOptions(
 	"get",
 	"/api/v1/stocks/{uid}/position",
 	{ params: { path: { uid: "e6123145-9665-43e0-8413-cd61b8aa9b13" } } },
 ).queryKey;
+
 const bondQueryKey = apiQueryClient.queryOptions(
 	"get",
 	"/api/v1/bonds/{uid}/position",
 	{ params: { path: { uid: "e6123145-9665-43e0-8413-cd61b8aa9b13" } } },
 ).queryKey;
+
 const bankCardsQueryKey = apiQueryClient.queryOptions(
 	"get",
 	"/api/v1/bank-cards",
@@ -48,6 +53,7 @@ const bankCardsQueryKey = apiQueryClient.queryOptions(
 		params: { query: { includeArchived: "false" } },
 	},
 ).queryKey;
+
 const unrelatedQueryKey = apiQueryClient.queryOptions(
 	"get",
 	"/api/v1/auth/me",
@@ -59,6 +65,7 @@ function renderSection(client: QueryClient) {
 		clear: vi.fn(),
 		refresh: () => Promise.resolve(true),
 	});
+
 	return render(
 		<MantineProvider>
 			<QueryClientProvider client={client}>
@@ -70,21 +77,22 @@ function renderSection(client: QueryClient) {
 
 function seededClient() {
 	const client = createTestQueryClient();
+	/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
 	client.setQueryData(brokerageAccountsQueryKey, [
-		(/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
-			{
-				id: "account-1",
-				name: "Основной счет",
-				openedOn: null,
-				type: "BROKERAGE",
-			}
-		/* eslint-enable unicorn/no-null */),
+		{
+			id: "account-1",
+			name: "Основной счет",
+			openedOn: null,
+			type: "BROKERAGE",
+		},
+		/* eslint-enable unicorn/no-null */
 	]);
 	client.setQueryData(portfolioQueryKey, { source: "previous-connection" });
 	client.setQueryData(stockQueryKey, { source: "previous-connection" });
 	client.setQueryData(bondQueryKey, { source: "previous-connection" });
 	client.setQueryData(unrelatedQueryKey, { id: "user-1" });
 	client.setQueryData(bankCardsQueryKey, [{ id: "bank-card-1" }]);
+
 	return client;
 }
 
@@ -92,18 +100,23 @@ describe("TbankConnectionSection", () => {
 	it("preserves cached status and a draft entered during a delayed failed refetch", async () => {
 		const status = { connected: true, connectedAt: "2026-08-14T00:00:00Z" };
 
-		const { promise: response, resolve: finishRefetch } = Promise.withResolvers<void>();
+		const { promise: response, resolve: finishRefetch }
+			= Promise.withResolvers<void>();
+
 		let reads = 0;
 		server.use(
 			http.get("*/api/v1/tbank-connection", async () => {
 				reads += 1;
+
 				if (reads === 1) {
 					await response;
+
 					return HttpResponse.json(
 						{ code: "TBANK_UNAVAILABLE" },
 						{ status: 503 },
 					);
 				}
+
 				return HttpResponse.json(status);
 			}),
 		);
@@ -141,11 +154,14 @@ describe("TbankConnectionSection", () => {
 		server.use(
 			http.get("*/api/v1/tbank-connection", () => {
 				reads += 1;
+
 				return reads === 1
 					? HttpResponse.json({ code: "TBANK_UNAVAILABLE" }, { status: 503 })
-					: HttpResponse.json((/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
-							{ connected: false, connectedAt: null }
-							/* eslint-enable unicorn/no-null */));
+					/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
+					: HttpResponse.json(
+							{ connected: false, connectedAt: null },
+							/* eslint-enable unicorn/no-null */
+						);
 			}),
 		);
 		renderSection(createTestQueryClient());
@@ -244,19 +260,24 @@ describe("TbankConnectionSection", () => {
 		const client = seededClient();
 
 		let isAborted = false;
-		const { promise: previousResponse, resolve: finishPrevious } = Promise.withResolvers<{ source: string }>();
+
+		const { promise: previousResponse, resolve: finishPrevious }
+			= Promise.withResolvers<{ source: string }>();
+
 		const previousRequest = client
 			.query({
 				queryFn: ({ signal }) => {
 					signal.addEventListener("abort", () => {
 						isAborted = true;
 					});
+
 					return previousResponse;
 				},
 				queryKey: operationsQueryKey,
 			})
 			// eslint-disable-next-line unicorn/prefer-await -- Attach the handler immediately and retain the pending promise for queue/race ordering.
 			.catch(() => {});
+
 		renderSection(client);
 
 		await screen.findByText("Не подключено");
@@ -302,7 +323,9 @@ describe("TbankConnectionSection", () => {
 	it("keeps DELETE recovery inside the dialog and preserves cache until successful retry", async () => {
 		let deletes = 0;
 
-		const { promise: response, resolve: finishDelete } = Promise.withResolvers<void>();
+		const { promise: response, resolve: finishDelete }
+			= Promise.withResolvers<void>();
+
 		server.use(
 			http.get("*/api/v1/tbank-connection", () =>
 				HttpResponse.json({
@@ -313,6 +336,7 @@ describe("TbankConnectionSection", () => {
 			http.delete("*/api/v1/tbank-connection", async () => {
 				deletes += 1;
 				if (deletes === 1) await response;
+
 				return deletes === 1
 					? HttpResponse.json({ code: "TBANK_UNAVAILABLE" }, { status: 503 })
 					: new HttpResponse(null, { status: 204 });
@@ -324,9 +348,11 @@ describe("TbankConnectionSection", () => {
 		fireEvent.click(
 			await screen.findByRole("button", { name: "Удалить подключение" }),
 		);
+
 		const dialog = await screen.findByRole("dialog", {
 			name: "Удалить подключение?",
 		});
+
 		await waitFor(() =>
 			// eslint-disable-next-line testing-library/no-node-access -- This assertion checks DOM structure, decoration or focus behavior that semantic queries cannot establish.
 			expect(dialog.contains(document.activeElement)).toBe(true),

src/features/tbank-connection/ui/TbankConnectionSection/TbankConnectionSection.tsx

@@ -10,7 +10,14 @@ import { TbankConnectionSectionLoaded } from "./TbankConnectionSectionLoaded";
 const TbankConnectionSection: FC = () => {
 	const viewModel = useTbankConnectionViewModel();
 	if (viewModel.state === "loading") return <TbankConnectionLoading />;
-	return viewModel.state === "error" ? <TbankConnectionError retry={viewModel.retry} /> : <TbankConnectionSectionLoaded {...viewModel} />;
+
+	return viewModel.state === "error"
+		? (
+				<TbankConnectionError retry={viewModel.retry} />
+			)
+		: (
+				<TbankConnectionSectionLoaded {...viewModel} />
+			);
 };
 
 export { TbankConnectionSection };

src/features/tbank-connection/ui/TbankConnectionSection/TbankConnectionSection.view.test.tsx

@@ -10,11 +10,13 @@ import {
 describe("TbankConnectionSection state views", () => {
 	it("renders loading and retries a status error", () => {
 		const retry = vi.fn();
+
 		const { rerender } = render(
 			<MantineProvider>
 				<TbankConnectionLoading />
 			</MantineProvider>,
 		);
+
 		expect(screen.getByRole("status", { name: "Загрузка" })).toHaveAttribute(
 			"aria-busy",
 			"true",

src/features/tbank-connection/ui/TbankConnectionSection/TbankConnectionSection.view.tsx

@@ -14,6 +14,7 @@ const TbankConnectionLoading: FC = () => {
 	return (
 		<LoadingSkeleton label={t("states.loadingTitle")}>
 			<Skeleton height={20} width="45%" />
+
 			<Skeleton height={36} radius="sm" width={140} />
 		</LoadingSkeleton>
 	);

src/features/tbank-connection/ui/TbankConnectionSection/TbankConnectionSection.vm.ts

@@ -6,9 +6,13 @@ function useTbankConnectionViewModel() {
 	const status = useAuthenticatedQuery({
 		...tbankConnectionQueryOptions(),
 	});
+
 	if (!status.data) {
-		return status.isPending ? { state: "loading" as const } : { retry: () => status.refetch(), state: "error" as const };
+		return status.isPending
+			? { state: "loading" as const }
+			: { retry: () => status.refetch(), state: "error" as const };
 	}
+
 	return {
 		refreshError: status.isError,
 		refreshing: status.isFetching,

src/features/tbank-connection/ui/TbankConnectionSection/TbankConnectionSectionLoaded.tsx

@@ -8,19 +8,11 @@ import {
 	Stack,
 	Text,
 } from "@mantine/core";
-import { useQueryClient } from "@tanstack/react-query";
-import { useEffect, useRef, useState } from "react";
-import { useForm } from "react-hook-form";
-import { useTranslation } from "react-i18next";
 
-import { ApiErrorCode, apiErrorCode, apiQueryClient, isApiErrorCode } from "@/shared/api";
+import { ApiErrorCode, isApiErrorCode } from "@/shared/api";
 
-import {
-	commitTbankConnectionBoundary,
-	type TbankConnectionStatus,
-} from "../../model/connection-boundary";
-
-enum ConnectionErrorCode { RequestFailed = "REQUEST_ERROR" }
+import { type TbankConnectionStatus } from "../../model/connection-boundary";
+import { useTbankConnectionSectionLoadedVm } from "./TbankConnectionSectionLoaded.vm";
 
 type TbankConnectionSectionLoadedProps = {
 	refreshError: boolean;
@@ -32,48 +24,29 @@ type TbankConnectionSectionLoadedProps = {
 const TbankConnectionSectionLoaded: FC<TbankConnectionSectionLoadedProps> = (
 	props,
 ) => {
-	const { status } = props;
-	const { t } = useTranslation();
-	const queryClient = useQueryClient();
-	const [isDeleteOpened, setIsDeleteOpened] = useState(false);
-	const removalButtonRef = useRef<HTMLButtonElement>(null);
-	const [requestError, setRequestError] = useState<null | string>(null);
 	const {
-		formState: { errors },
-		handleSubmit,
+		errors,
+		isConnected,
+		isDeleteOpened,
+		isPending,
+		onCloseDisconnect,
+		onConfirmDisconnect,
+		onOpenDisconnect,
+		onSubmit,
 		register,
-		reset,
-	} = useForm<{ token: string }>();
-	const update = apiQueryClient.useMutation("put", "/api/v1/tbank-connection", {
-		onError: error => setRequestError(apiErrorCode(error) ?? ConnectionErrorCode.RequestFailed),
-		onSuccess: (data) => {
-			commitTbankConnectionBoundary(queryClient, data);
-			reset();
-		},
-	});
-	const remove = apiQueryClient.useMutation(
-		"delete",
-		"/api/v1/tbank-connection",
-		{
-			onSuccess: () => {
-				commitTbankConnectionBoundary(queryClient, {
-					connected: false,
-					connectedAt: /* eslint-disable-line unicorn/no-null -- The disconnected API snapshot requires a null connection timestamp. */ null,
-				});
-				setIsDeleteOpened(false);
-			},
-		},
-	);
-	const unavailableMessage = isApiErrorCode(requestError, ApiErrorCode.TbankUnavailable) ? "tbank.unavailable" : "tbank.requestError";
-	const isPending = update.isPending || remove.isPending;
-	const isConnected = status.connected;
-	useEffect(() => {
-		if (isDeleteOpened && remove.isError) removalButtonRef.current?.focus();
-	}, [isDeleteOpened, remove.isError]);
+		removalButtonRef,
+		remove,
+		requestError,
+		status,
+		t,
+		unavailableMessage,
+		update,
+	} = useTbankConnectionSectionLoadedVm(props);
 
 	return (
 		<Stack mt="xl">
 			<Text fw={600}>{t("tbank.title")}</Text>
+
 			<Text size="sm">
 				{isConnected
 					? t("tbank.connected", {
@@ -83,18 +56,22 @@ const TbankConnectionSectionLoaded: FC<TbankConnectionSectionLoadedProps> = (
 						})
 					: t("tbank.disconnected")}
 			</Text>
+
 			<Text c="dimmed" size="sm">
 				{t("tbank.hint")}
 			</Text>
+
 			{props.refreshing && (
 				<Text c="dimmed" role="status" size="sm">
 					{t("tbank.refreshing")}
 				</Text>
 			)}
+
 			{props.refreshError && (
 				<Alert aria-live="polite" color="orange" role="status">
 					<Stack gap="sm">
 						<Text>{t("tbank.refreshError")}</Text>
+
 						<Button
 							disabled={props.refreshing || isPending}
 							onClick={props.retry}
@@ -105,12 +82,8 @@ const TbankConnectionSectionLoaded: FC<TbankConnectionSectionLoadedProps> = (
 					</Stack>
 				</Alert>
 			)}
-			<form
-				onSubmit={handleSubmit(({ token }) => {
-					setRequestError(null);
-					update.mutate({ body: { token } });
-				})}
-			>
+
+			<form onSubmit={onSubmit}>
 				<fieldset disabled={isPending}>
 					<Stack>
 						<PasswordInput
@@ -118,6 +91,7 @@ const TbankConnectionSectionLoaded: FC<TbankConnectionSectionLoadedProps> = (
 							{...register("token", { required: t("tbank.tokenRequired") })}
 							error={errors.token?.message}
 						/>
+
 						{requestError && (
 							<Alert color="red">
 								{t(
@@ -127,42 +101,43 @@ const TbankConnectionSectionLoaded: FC<TbankConnectionSectionLoadedProps> = (
 								)}
 							</Alert>
 						)}
+
 						<Button loading={update.isPending} type="submit">
 							{t(isConnected ? "tbank.replace" : "tbank.connect")}
 						</Button>
+
 						{isConnected && (
-							<Button
-								color="red"
-								onClick={() => {
-									remove.reset();
-									setIsDeleteOpened(true);
-								}}
-								variant="outline"
-							>
+							<Button color="red" onClick={onOpenDisconnect} variant="outline">
 								{t("tbank.delete")}
 							</Button>
 						)}
 					</Stack>
 				</fieldset>
 			</form>
+
 			<Modal
-				closeButtonProps={{ "aria-label": t("tbank.close"), "disabled": isPending }}
+				closeButtonProps={{
+					"aria-label": t("tbank.close"),
+					"disabled": isPending,
+				}}
 				closeOnClickOutside={!isPending}
 				closeOnEscape={!isPending}
-				onClose={() => !isPending && setIsDeleteOpened(false)}
+				onClose={onCloseDisconnect}
 				opened={isDeleteOpened}
 				title={t("tbank.deleteTitle")}
 			>
 				<Stack>
 					<Text>{t("tbank.deleteText")}</Text>
+
 					{remove.isError && (
 						<Alert color="red">{t("tbank.requestError")}</Alert>
 					)}
+
 					<Button
 						color="red"
 						disabled={isPending}
 						loading={remove.isPending}
-						onClick={() => remove.mutate({})}
+						onClick={onConfirmDisconnect}
 						ref={removalButtonRef}
 					>
 						{t("tbank.deleteConfirm")}

src/features/tbank-connection/ui/TbankConnectionSection/TbankConnectionSectionLoaded.vm.ts

@@ -0,0 +1,116 @@
+import { useQueryClient } from "@tanstack/react-query";
+import { useEffect, useRef, useState } from "react";
+import { useForm } from "react-hook-form";
+import { useTranslation } from "react-i18next";
+
+import {
+	ApiErrorCode,
+	apiErrorCode,
+	apiQueryClient,
+	isApiErrorCode,
+} from "@/shared/api";
+
+import {
+	commitTbankConnectionBoundary,
+	type TbankConnectionStatus,
+} from "../../model/connection-boundary";
+enum ConnectionErrorCode {
+	RequestFailed = "REQUEST_ERROR",
+}
+
+type TbankConnectionSectionLoadedProps = {
+	refreshError: boolean;
+	refreshing: boolean;
+	retry: () => void;
+	status: TbankConnectionStatus;
+};
+
+function useTbankConnectionSectionLoadedVm(
+	props: TbankConnectionSectionLoadedProps,
+) {
+	const { status } = props;
+	const { t } = useTranslation();
+	const queryClient = useQueryClient();
+	const [isDeleteOpened, setIsDeleteOpened] = useState(false);
+	const removalButtonRef = useRef<HTMLButtonElement>(null);
+	const [requestError, setRequestError] = useState<null | string>(null);
+
+	const {
+		formState: { errors },
+		handleSubmit,
+		register,
+		reset,
+	} = useForm<{ token: string }>();
+
+	const update = apiQueryClient.useMutation("put", "/api/v1/tbank-connection", {
+		onError: error =>
+			setRequestError(apiErrorCode(error) ?? ConnectionErrorCode.RequestFailed),
+		onSuccess: (data) => {
+			commitTbankConnectionBoundary(queryClient, data);
+			reset();
+		},
+	});
+
+	const remove = apiQueryClient.useMutation(
+		"delete",
+		"/api/v1/tbank-connection",
+		{
+			onSuccess: () => {
+				commitTbankConnectionBoundary(queryClient, {
+					connected: false,
+					connectedAt:
+						// eslint-disable-next-line unicorn/no-null -- The disconnected API snapshot requires a null connection timestamp.
+						null,
+				});
+				setIsDeleteOpened(false);
+			},
+		},
+	);
+
+	const unavailableMessage = isApiErrorCode(
+		requestError,
+		ApiErrorCode.TbankUnavailable,
+	)
+		? "tbank.unavailable"
+		: "tbank.requestError";
+
+	const isPending = update.isPending || remove.isPending;
+	const isConnected = status.connected;
+	useEffect(() => {
+		if (isDeleteOpened && remove.isError) removalButtonRef.current?.focus();
+	}, [isDeleteOpened, remove.isError]);
+
+	const onSubmit = handleSubmit(({ token }) => {
+		setRequestError(null);
+		update.mutate({ body: { token } });
+	});
+
+	const onOpenDisconnect = () => {
+		remove.reset();
+		setIsDeleteOpened(true);
+	};
+
+	const onCloseDisconnect = () => !isPending && setIsDeleteOpened(false);
+	const onConfirmDisconnect = () => remove.mutate({});
+
+	return {
+		errors,
+		isConnected,
+		isDeleteOpened,
+		isPending,
+		onCloseDisconnect,
+		onConfirmDisconnect,
+		onOpenDisconnect,
+		onSubmit,
+		register,
+		removalButtonRef,
+		remove,
+		requestError,
+		status,
+		t,
+		unavailableMessage,
+		update,
+	};
+}
+
+export { useTbankConnectionSectionLoadedVm };